Not applicable.
Not applicable.
1. Field of the Invention
The present invention generally relates to a method and apparatus for attaching a vehicle door to a vehicle frame or body-in-white. More specifically, this invention teaches a method and apparatus for attaching an automotive vehicle door whereby the door is attached at a net or best fit position such that the door is correctly centered and aligned with respect to the door opening in the vehicle frame, and associated feature lines align with adjacent panels upon attachment thereto without the need for a slip plane adjustment of the door on the vehicle frame.
2. Description of the Related Art
Conventionally, assembly of motor vehicle doors to a door opening has involved implementation of slip planes to facilitate assembly of the door to the vehicle. The door typically includes an outer panel joined to an inner panel by hem flanging the edge of the outer panel over the edge of the inner panel. The inner panel includes a front hinge mounting surface with upper and lower hinges mounted thereto and a rear latch mounting surface with a latch mounted thereto. The door opening is defined by a front hinge pillar, a rear latch pillar, a top roof rail and a bottom sill.
It is well known in the art to include slip planes in the door hinges or the hinge pillar. The slip planes permit fore/aft and up/down adjustment of the hinge as necessary to permit the door to be fitted within the body opening. The slip planes are typically slotted holes that are elongated in the direction of adjustment. For example, hinge pillar attachment holes in the hinge that are size specific up/down and elongated fore/aft locate the door in a fixed up/down position and permit adjustment of the door fore/aft relative to the fender and rear quarter panel.
Attachment bolts loosely attach the hinge to the hinge pillar such that the door is adjustable within the limits of the slotted attachment holes. While the door is loosely attached, an operator adjusts the hem edge of the door panel to a predetermined feature (typically the fender) using setting fixtures, a gap tool, and/or subjective trial and error inspection. After establishing a subjective proper position of the door, the operator tightens the attachment bolts thereby attaching the door hinges to the hinge pillar in the adjusted position.
The conventional method for adjusting the door within the door opening described above is both inefficient and subjective. The adjustment of the door typically requires an additional operator dedicated solely to aligning the door to the door opening, and the process of adjusting the door delays the assembly line. Additionally, conventional door alignment is subjective in that the process relies in part on the operator""s judgment and inspection. Finally, the process of tightening the bolts attaching the door hinges to the hinge pillar applies torque to the hinges that can cause movement of the hinges and thereby create an improperly adjusted door.
U.S. Pat. No. 6,317,925 to Pietryga, et al. teaches an alternative to conventional elongated slot slip planes described above. More specifically, Pietryga, et al. teach a hinge trim system used to cover a hinge whereby portions of the hinge trim system form slip planes. The slip planes permit fore/aft and up/down adjustment of the hinge as necessary to permit the door to be fitted within the body opening. Cross-car adjustments can be accomplished by pivoting the hinge to the desired orientation.
The invention disclosed by Pietryga, et al. teaches a method for covering a non-styled exposed hinge, and further teaches a method for adjusting a door within a body opening based on an improved slip plane configuration. However, Pietryga, et al. still suffers from all of the problems associated with slip plane adjustment based on elongated slots discussed above.
U.S. Pat. No. 4,375,716 to Armstrong, et al. teaches a method by which a vehicle door may be precisely hinged to the vehicle body with the adjacent appearance features of the closure and the body precisely aligned and spaced relative to one another.
Armstrong, et al. provides a fixture that establishes positioning of hinge attachment holes in a body side panel relative to the door openings. The fixture includes locating pads that engage predetermined locations on the door openings to position the body side panel in up/down and fore/aft directions. Locating pins in the fixture represent optimal up/down and fore/aft position for the hinge attachment holes relative to the locating pads. Anchor plates having hinge attachment holes therein are loaded onto locating pins in the fixture and welded to the body side panel. In the manner described, Armstrong et al. position the hinge attachment holes in the anchor plates up/down and fore/aft relative to the door openings. After the location of the hinge attachment holes are set, the body side panel is toy tabbed and welded to the other components forming the frame in a framing fixture.
The cross-car position of the hinges are set in an offline door fixture relative to appearance features of the door. The up/down and fore/aft position of a frame attachment hole in the hinge is established in an offline piercing fixture. A door with hinges attached thereto is placed into the piercing fixture. Locating blocks in the piercing fixture engage a surface of the door outer panel and the leading edge of the door to establish fore/aft position. An additional locating block sets the door up/down position relative to top and bottom edges of the door. Clamping and locating fixtures hold the door hinge at a position simulating the closed position of the door. A piercing tool punches a size specific hole in the door hinge in a position relative to the door surfaces located by the fixture locating blocks.
The door is simultaneously attached and adjusted to the door opening by inserting a bolt through the size specific hole in the door hinge and the size specific hole in the anchor plate. As the position of the size specific hole in the anchor plate is adjusted up/down and fore/aft relative to the door opening, a door attached to the adjusted size specific hole in the anchor plate is automatically located up/down and fore/aft with respect to the door opening. Additionally, because the position of the size specific hole in the door hinge is adjusted up/down and fore/aft relative to the edges of the door, the door is automatically adjusted relative to adjacent body panels. Armstrong et al. teaches a method for attaching and adjusting a door within a door opening that does not rely on a slip plane or subjective operator inspection.
While Armstrong, et al. provides significant advantages over conventional slip plane based methods of attachment, it failed to account for the variation introduced when the frame is welded in the framing fixture and the variation introduced when the bolt attaching the door hinge to the anchor plate is tightened. Although the anchor plate is initially located relative to the door openings, the heat generated by the numerous welding operations (as many as 3,000) in the framing fixture deforms the body side panel in an unpredictable manner such that the hinge attachment holes in the anchor plate do not necessarily remain in the same relative position. Additionally, the process of tightening the bolts attaching the door hinges to the hinge pillar applies torque to the fastening bolts. As the fastening bolts frictionally engage the hinge plates, the torque applied to the fastening bolts can cause rotation of the hinge plates and thereby take a properly adjusted door out of alignment. Also, the specific door as built by Armstrong et al. must be installed in a specific body side opening. The coordination of the doors with corresponding vehicle bodies is an absolute necessity and an improperly coordinated door that will not align properly with the body side opening leads to excessive offline repair costs after the body is completed.
From the above, it can be appreciated that the related art methods discussed are not optimized to accurately and efficiently assemble any door in any door opening that has unknown tolerance deviations resulting from its own manufacturing processing. Therefore, what is needed is a method and apparatus for assembling a door, which does not rely on subjective slip plane adjustment in the vehicle frame, can be installed on any vehicle frame opening, does not rely on frame locations established before the frame is welded, and that can maintain proper alignment while the hinge attachment bolts are tightened.
According to the preferred embodiment of the present invention, there is provided an improved method and apparatus for attaching vehicle doors to a vehicle body often referred to as a body-in-white, such that the doors are attachable at a net location. Furthermore, the apparatus includes a feature for maintaining and ensuring proper door positioning while the hinge attachment bolts are tightened to net locate the door in its best fit assembly position.
The method described herein includes the steps of utilizing a new net X-Y-Z coordinate system for a vehicle frame after the frame is welded in a framing fixture, and piercing or forming upper and lower net positioned locating slots in hinge pillars of the vehicle frame relative to the new net X-Y-Z coordinate system. The method further includes the steps of forming a locating nubbin in upper and lower hinges relative to the door, and aligning the locating nubbins with the locating slots during attachment of the door to the vehicle frame. In the context of the following summary of the invention, reference to the fore/aft (X), cross-car (Y), and up/down (Z) axes, as well as the relative terms front, rear, top and bottom, apply to a component as viewed in final body position unless otherwise specified.
The new net X-Y-Z coordinate system is advantageously established after the frame is welded in the framing fixture so that variation introduced during the welding and assembly process can be balanced out and therefore disregarded. A position detecting apparatus on an assembly line is adjustable up/down, fore/aft and cross-car relative to the vehicle frame. Locating pins of the position detecting apparatus engage net locating holes or features of the vehicle frame to establish the new net X-Y-Z coordinate system for each individual vehicle frame in its as built condition. The position detecting apparatus adjusts to locate relative to selected body-in-white locating features and after locating, plug into associated sockets and lock in place to establish a new net X-Y-Z coordinate system and remain in the locked position for the duration of the assembly process on a particular vehicle. Work performing devices attached to the position detecting apparatus are then located net with respect to the new net X-Y-Z coordinate system established for the specific vehicle frame to perform work on the vehicle frame.
The work performing devices punch the net locating slots in the hinge pillar relative to the new net X-Y-Z coordinate system. As the locating slots are formed relative to the new net X-Y-Z coordinate system, their position is also net such that the locating slots are at a new net position relative to the newly established coordinate X-Y and Z for a specific vehicle frame. The upper locating slot is size specific in both the fore/aft and up/down directions whereby engagement with the corresponding nubbin on the upper hinge locates the door both fore/aft and up/down. The lower locating slot is size specific in only the fore/aft direction and oversized in the up/down direction whereby the corresponding nubbin on the lower hinge locates in the lower slot only in the fore/aft direction to avoid an interference condition when both nubbins are mounted in the slots.
According to the preferred embodiment, the locating nubbins in the upper and lower hinges are positioned relative to the door assembly in an offline door fixture. The offline door fixture locates the door on a Class A surface on the door outer panel and on the peripheral hemmed edge. The offline door fixture further includes a master plate simulating the net hinge pillar in the vehicle frame, and upper and lower punches for making the upper and lower locating nubbins on the hinges.
The hinges include a first hinge link pivotally connected to a second hinge link. The first hinge link has oversize door attachment holes through which the hinges are loosely attached to the inner door assembly. The door attachment holes are slotted such that the loosely attached hinges can be set to a net cross-car position as discussed hereinafter. Additional oversized holes are provided in the second hinge link for later attachment to the body.
In the preferred embodiment, the door assembly with the hinges loosely attached thereto is loaded into the offline door fixture such that the bottom of the door rests on an up/down net pad, a Class A surface on the door outer panel locates on a cross-car net pad, and the leading edge of the outer door panel is located by the fore/aft locating block so as to net locate the door in the up/down and fore/aft directions. It is contemplated that any convenient method may be used to net locate the door in the door fixture. For example, it is possible to locate the door in the door fixture up/down and fore/aft by net locating on the Class A contour surface of the outer panel or use a feature line on the outer panel to net locate the door in the up/down direction. Alternatively, a window opening feature such as a belt line can also be used.
The hinges are set net cross-car to the master plate positioned to simulate the hinge pillar of the vehicle frame. While still loosely attached to the door assembly, the hinges are moved cross-car into contact with the master plate and tightened to the door assembly thereby setting the net cross-car position of the door relative to the net hinge pillar position. The up/down locators in the offline door fixture locate a door feature at the front of the door and rear of the door to establish up/down position of a feature line on the outer door panel relative to the bottom of the door. The door is secured in the fixture and the upper and lower punches operate to form the locating nubbins in the hinges relative to the up/down and fore/aft position established by the locating technique described above in the offline fixture.
After the door is processed through the offline fixture, the door is attached to any vehicle frame by mounting the second hinge link of the upper and lower hinges to the hinge pillar on the vehicle frame such that the locating nubbins are inserted into the locating slots. As all door assembly attachment/locating points are in a net position, and the locating slot is positioned relative to the newly established net position for the particular vehicle, the door is automatically set up/down and fore/aft to the body at a best fit position, that is, gapping between the door and the opening is constant all the way around the door since the gap has been averaged out by being able to locate net to the opening. Also, the door will be flush to the adjacent panels and if a feature line has been identified as critical, this line will line-up with similar feature lines in adjacent panels. Additionally, because the cross-car position of the door has already been set net relative to the master plate simulating the hinge pillar in the offline fixture, the net cross-car position of the door is automatically obtained upon attachment. Finally, any frictional movement due to the torque applied to the second hinge link during attachment of the door to the frame cannot cause rotation of the hinge link because of the engagement of the locating nubbins within the locating slots.
It is an object of the present invention to provide a method and apparatus for establishing a net position for attaching a door to a vehicle body thereby eliminating slip plane adjustment of the door in the vehicle frame and associated subjective flush and fit adjustments.
It is another object to provide a method and apparatus for attaching a door to a vehicle body such that the door is net positioned to the body upon attachment.
It is still another object to provide a method and apparatus for attaching a door to a vehicle frame such that the process of tightening the attachment screws does not alter alignment of the door with respect to the door opening.
It is yet another object to provide a method and apparatus for adjusting a door on a vehicle body that does not rely on subjective operator adjustment.
It is a further object to provide a method and apparatus for attaching any door to any vehicle frame opening such that it is not necessary to coordinate specific doors with specific vehicle frames.
It is still a further object to provide a method and apparatus for utilizing a net body coordinate system on a vehicle body after the body-in-white has been welded such that all outer body panels such as doors, hoods, fenders, decklids, liftgates, bumpers, and/or fascias can be attached with established net features without the need for subjective flush and fitness adjustments.
These objects and other features, aspects, and advantages of this invention will be more apparent after a reading of the following detailed description, appended claims, and accompanying drawings.